Proteolytic and genetic variation of the alpha-2-antiplasmin C-terminus in myocardial infarction

Abstract

Alpha-2-antiplasmin (α2AP) undergoes both N- and C-terminal cleavages, which significantly modify its activities. Compared with other Ser protease inhibitors (serpins), α2AP contains an ∼ 50-residue-extended C-terminus, which binds plasmin(ogen). We developed 2 new ELISAs to measure the antigen levels of free total α2AP and free C-terminally intact α2AP to investigate whether α2AP antigen levels or α2AP C-terminal cleavage were associated with myocardial infarction (MI) in 320 male MI survivors and 169 age-matched controls. Patients had 15.2% reduced total α2AP antigen levels compared with controls (93.8 vs 110.6 U/dL, P